Integrated digital laser

Abstract

A laser device includes: a substrate formed from material transparent at a laser wavelength; a first reflecting layer to reflect at least some incident radiation at the laser wavelength; a layer including a gain medium for providing stimulated emission of radiation at the laser wavelength, and positioned between the first reflecting layer and the substrate; a second reflecting layer on an opposite side of the substrate from the first reflecting layer to reflect at least some incident radiation at the laser wavelength; a spatial light modulator in an optical cavity comprising the first and second reflecting layers, and comprising an array of elements each corresponding to a different path for radiation in the optical cavity; and a computer controller that, during operation, causes the spatial light modulator to selectively vary an intensity or phase of radiation in the optical cavity to provide variable transverse spatial mode output of the radiation.

What is claimed is: 
     
       1. A laser device with variable transverse spatial mode output, comprising:
 a substrate formed from a material transparent at a laser wavelength; 
 a first reflecting layer supported by the substrate, the first reflecting layer being configured to reflect at least some incident radiation at the laser wavelength; 
 a layer comprising a gain medium for providing stimulated emission of radiation at the laser wavelength, the layer comprising the gain medium being positioned between the first reflecting layer and the substrate; 
 a second reflecting layer supported by the substrate on an opposite side of the substrate from the first reflecting layer, the second reflecting layer being configured to reflect at least some incident radiation at the laser wavelength; 
 a spatial light modulator supported by the substrate and positioned in a path of radiation in an optical cavity comprising by the first and second reflecting layers, the spatial light modulator comprising an array of elements each corresponding to a different path for radiation in the optical cavity; and 
 a computer controller in communication with the spatial light modulator, 
 wherein during operation the computer controller causes the spatial light modulator to selectively vary an intensity or phase of radiation in each of the radiation paths in the optical cavity to provide variable transverse spatial mode output of the radiation from the laser device. 
 
     
     
       2. The laser device of  claim 1 , wherein the spatial light modulator is on the opposite side of the substrate as the layer comprising the gain medium. 
     
     
       3. The laser device of  claim 2 , wherein the spatial light modulator is a transmissive spatial light modulator. 
     
     
       4. The laser device of  claim 1 , wherein the spatial light modulator is on the same side of the substrate as the layer comprising the gain medium. 
     
     
       5. The laser device of  claim 4 , wherein the spatial light modulator is a reflective spatial light modulator. 
     
     
       6. The laser device of  claim 4 , wherein the second reflecting layer is arranged to reflect incident radiation emitted by the gain medium toward the spatial light modulator and to reflect incident radiation reflected by the spatial light modulator toward the gain medium. 
     
     
       7. The laser device of  claim 1 , wherein the first reflecting layer comprises a Bragg reflector for radiation at the laser wavelength. 
     
     
       8. The laser device of  claim 1 , wherein the second reflecting layer comprises a reflective grating. 
     
     
       9. The laser device of  claim 8 , wherein the reflective grating is a chirped grating. 
     
     
       10. The laser device of  claim 1 , wherein the gain medium comprises a quantum well layer. 
     
     
       11. The laser device of  claim 1 , further comprising a first electrode layer between the layer comprising the gain medium and the substrate. 
     
     
       12. The laser device of  claim 11 , further comprising a second electrode layer, the first and second electrode layers being on opposing sides of the layer comprising the gain medium. 
     
     
       13. The laser device of  claim 11 , wherein one or both of the first and second electrode layers are patterned electrode layers. 
     
     
       14. The laser device of  claim 11 , wherein the first electrode layer is formed from an electrically-conductive material transparent at the laser wavelength. 
     
     
       15. The laser device of  claim 11 , wherein the first electrode layer comprises an aperture for the passage of laser radiation. 
     
     
       16. The laser device of  claim 1 , wherein the first or second reflecting layer is a partial reflecting layer for radiation at the laser wavelength. 
     
     
       17. The laser device of  claim 1 , wherein the laser wavelength is in a range from 250 nm to 5,000 nm. 
     
     
       18. The laser device of  claim 1 , wherein, during operation, the gain medium is electrically-pumped, optically-pumped, or pumped using an electron beam. 
     
     
       19. A display comprising the laser device of  claim 1 . 
     
     
       20. An optical communication system comprising the laser device of  claim 1 . 
     
     
       21. A method of forming a laser device, comprising:
 forming a light emitting module comprising a first reflecting layer and a layer comprising a gain medium, the first reflecting layer being configured to reflect at least some incident radiation at a laser wavelength and the layer comprising the gain medium being configured to provide stimulated emission of radiation at the laser wavelength; 
 forming a spatial light modulator; and 
 assembling the laser device by attaching the light emitting module and spatial light modulator to a common substrate layer formed from a material transparent at the laser wavelength such that the spatial light modulator is positioned in a path of radiation in an optical cavity defined by the first reflecting layer and a second reflector, the spatial light modulator comprising an array of elements each corresponding to a different path for radiation through the substrate layer in the optical cavity. 
 
     
     
       22. The method of  claim 21 , wherein forming the light emitting module comprises sequentially forming multiple layers on top of each other and patterning at least some of the layers. 
     
     
       23. The method of  claim 21 , wherein forming the laser device comprises forming multiple devices using a common substrate and dicing the substrate to provide multiple individual devices. 
     
     
       24. The method of  claim 21 , wherein the spatial light modulator comprises the second reflector. 
     
     
       25. The method of  claim 21 , wherein the second reflector is a second reflector layer and the spatial light modulator is a transmissive spatial light modulator and a path of the laser radiation between the first and second reflecting layers. 
     
     
       26. The method of  claim 21 , wherein the spatial light modulator and light emitting module are disposed on opposing sides of the common substrate. 
     
     
       27. The method of  claim 21 , wherein the spatial light modulator and light emitting module are disposed on the same side of the common substrate and an additional reflector is disposed on the opposite side of the substrate and arranged to direct light from the light emitting module to the spatial light modulator and vice versa.